Thanks for bringing this up. 
Depends.
- For file management and converting I use Comicrack (http://comicrack.cyolito.com/).
- For quick display and shell thumbnail generation CDisplayEx (http://www.cdisplayex.com/).
But real reading, meaning living room and, pardon me hmhmhmh - bathroom, is done using tablet. For that purpose, you may use ComicRack as well, and then use its Android device manager tool. Frankly, I haven't found it to be real useful.
So, for real comic book file management Directory Opus is like 'THE perfectest' tool. So, I made the script that can help optimize bunch of files to whatever hardware one owns: meaning reducing usually insane page pixels sizes so the bunch of comic books would fit to XDHC flash drive which is always short of capacity. Then at the Android size, Perfect Viewer is currently perfect comic book reading companion (https://play.google.com/store/apps/details?id=com.rookiestudio.perfectviewer).
Optimization/Conversion script: